Context Dependent Image Caching

1. A method for managing an image cache in a display computer in a computer system having a host computer and a display computer, the method comprising: calculating a quality rating for an image; determining if it is appropriate to cache said image on the display computer, wherein said determination is based on said quality rating; transmitting said image to the display computer; and transmitting instructions to the display computer to cache said image if appropriate wherein said quality rating is calculated based on a ratio of the area of a constant region to the area of said image, wherein said constant region keeps track of portions of an image that do not change during successive copies to a screen.

2. An apparatus for managing an image cache in a display computer in a computer system having a host computer and a display computer, the apparatus comprising: an image quality rating calculator; a cache image appropriateness determiner coupled to said image quality rating calculator; an image transmitter coupled to said image quality rating calculator; and a cache instruction transmitter coupled to said cache image appropriateness determiner wherein said image quality rating calculator includes: an image constant region area-to-image area ratio measurer.

3. An apparatus for managing an image cache in a display computer in a computer system having a host computer and a display computer, the apparatus comprising: means for calculating a quality rating for an image; means for determining if it is appropriate to cache said image on the display computer, wherein said determination is based on said quality rating; means for transmitting said image to the display computer; and means for transmitting instructions to the display computer to cache said image if appropriate wherein said quality rating is calculated based on a ratio of the area of a constant region to the area of said image, wherein said constant region keeps track of portions of an image that do not change during successive copies to a screen.